Not too long ago, users on the Neowin.net forums started complaining about not being able to send YouTube links to their contacts on Windows Live Messenger. I was skeptic at first, but it didn’t take me very long to confirm that is indeed the case.
As you can see, any messages that contain in text or links to “www.youtube.com” fails to be delivered.
Curious as a cat, I loaded up a network packet sniffer to find out exactly what’s going on behind the scenes. Technically, the message packets are in fact sent to the Messenger servers (so it’s not being blocked at your client), but the server sends back a negative acknowledgment (NAK) packet instead of an acknowledgment (ACK) packet. Simply speaking, the server is refusing the message.
As some people may recall, in 2006 there was a report quoting MSN Sweden admitting Microsoft is “censoring” messages it deems a security threat. How it does this is by matching messages with a known list of text strings which are commonly found in phishing and malware sites such as “download.php”. Microsoft doesn’t publishes which strings are on this list for obvious reasons, but a comprehensive list of known blocked strings can be found here.
We all love a good conspiracy, but I don’t think anyone at Microsoft was dumb enough to do this deliberately to undermine Google. On the other hand, even if it was an accident, how do you ever trust this system?
Update (11/5/08): Not surprisingly YouTube links are working again.
Update 2: The Windows Live Messenger blog published a post admitting the problem which they claim was entirely controlled by a third party and their process of blocking harmful URLs. Another good reason to outsource.

Comments for "Windows Live Messenger blocks www.youtube.com (Update) Everything back to normal"
fiji
That is just insane!
James
Just found this, this morning, I’m sure there is a lawsuit just waiting to happen….
jake
I can send youtube links.
Maybe you all just have fucked up computers?
Tobias
No, it’s you that’s stuffed Jake =[
You need to include the http:// in the link, otherwise it doesn’t filter it - and 90% of people are too lazy to copy paste the link anyway.
Microsoft pigs.
mrmckeb
@Tobias
I send my friend youtube links all the time… I copy and paste the links - wouldn’t that be the ‘lazy’ way?
“Microsoft pigs”?
Philizz
I noticed last night… This is just insane…
(location: Holland)
Medea
Add deviantart.com and googlepages.com to that. And xanga. :/
Tobias
Add mediafire.com to that.
Although I think that was previously done.
Looking for more
webdeveloper
Instead of using http://youtube.com/ just say http://youtube.info
Tobias
Ebuddy.com is blocked, too.
mrmckeb
So what do we think it is? Must be a malfunction of some sort… seriously, Microsoft wouldn’t do this intentionally.
John
“Just found this, this morning, I’m sure there is a lawsuit just waiting to happen….”
Haha, you’re fucking retarded.
Tobias
They’ve done it intentionally.
I theorise it’d directly related to the release of Microsoft Soapbox.
Jason Cox
That’s weird because I received a few YouTube links yesterday…
Hamcha
Solution: Change Client or use my little script: http://video.netcucu.com
Into the site there are the guide to use, it work fine.
Pedro Valente
This is happening with me too.
I can’t believe Microsoft did it for porpouse, it may be an error on MSN servers.
From Brazil.
Glen Harness
Up until yesterday I was able to send youtube links to my wife. Then all of a sudden I couldn’t. I finally got around it by enclosing the whole thing in quotes, like this: “http://www.youtube.com/watch?v=EpGH02DtIws”
David
I deleted the http:// out of the URL, and still, it does not send me YouTube links.
Any solution to this?! :/
David
Oh.. missed Glen’s comment..
Thanks Glen.. i’ll use it
AkuaGuen
of course this muther fockers won´t do anything to change that bastard behavior, so just copy the link and paste it just like this youtube.com/watch?v=mBBn35m0CFo&feature=dir without www and without http:// and tell the other party to copy and paste the text into the browser, then hit Enter.
vishal
try sending linux_fcuks_vista.com …… that is also not workin
Raymond Vrolijk
I found out that I couldn’t send a Youtoube link to one of my contacts.
I googled on “msn block youtube” and found this site.
My location is The Hague, The Netherlands
York
Utterly unbelieveable, microsoft have stepped way over the line here.
Like most companies who are allowed to have a monopoly over certain markets they will eventually hold thier customers hostage to spite thier competitors.
666
That’s what you get for using Microshitware.
Dan
Just use a different P2Pclient, ICQ, AOL or whatever, M$ have stepped over the line this time!
Brian
@Dan - Exactly. I only use MSN Messenger when I need to get into contact with someone that isn’t on another protocol. I used to use ICQ all the time and IMO it’s the best client/protocol out there. I just wish more people would have realized it back then, instead of “oh hey, my computer comes with MSN Messenger, I guess I’m supposed to use that.”
@John - You’re a fucking idiot buddy. If you have something to say (ie. Why this isn’t a lawsuit situation) then by all means say something. Ripping on others for no good reason just makes you look like an ass. It’s people like you that make me wonder if the anti net-neutrality people aren’t a little bit right. If everyone was the same person on the internet as they were in real life, I bet the number of trolls and lamers would go down exponentially.
Grem
I’ve been a supporter of Microsoft over the years, excusing some of their ‘foibles’, but this sort of thing really pisses me off. I’m gonna start joining the Linux brigade and boycott as much of their shit as possible.
Gregor
I’ve always thought that Microsoft were kinda gay. Now they proved it. THEY’RE FUCKIN EVIL =O
Lg
THE BLOCK IS GONE !!
checked it on 20:54 here in the Netherlands
LIam
I send links all the time… no block here
LIam
Forgot to say I am from the UK
marijan
youtube.com works for me
someone
Horrible Microsoft continues to ruin its own reputation. Just today itself my mom wanted to show me a video and tried sending me the link and was bewildered. She then had to use TinyURL and before that I had to explain to her what TinyURL is. All thanks to Microsoft.
Peter
youtube links works for me now (They didn’t before) but not other links like googlepages and ebuddy.
Ryan
They just want to prevent anymore people from getting rick roll’d
leonidas.g
Greece/Hungary/France works now they must have fixed it. it didnt work a couple of hours ago
Daniel R
Doesn’t happen to any of my MSN Messenger Line contacts.
Nick
Uhm there are more site’s blocked.. doesn’t this mean that it can be a server problem?
When Microsoft realy blocks links via WLM.. they’re dead! People will find other irc clients. People will hate M$ more than they do now
Luke
Problem non-existant for me, besides I seriously doubt MS would block youtube…
Fabeme
Ow, come one ! This is certainly a server error ! Misconfiguration or something bad happened on MS servers. Stop screaming evil. Unless their is an official statement from MS saying they are blocking thoses websites deliberatly.
I can send and receive Youtube likes now, so something is getting fixed. And the fact that many other websites, related to google apparently, are blocked certainly come from an automated rule that didn’t go well.
We can still breath (for few years), we can still eat (few years too), this is not death…
becn
http://www.youtube.com/* was being blocked to me last night, and I used Pidgen on linux. But I could send many other urls.
How can a random “server” proplem explain that most url’s are transmitted fine - but some sites don’t. The only thing I can think of is that some bozo added youtube to a filter list on the msn servers. That’s not something you do “accidently”. Someone added it
Just because a conspiracy is alleged does NOT make it nuts!
DavidG
Well when I send http://www.youtube.com there are no problems.
Maybe it’s cuz I’m in Jamaica. I dunno.
vasudev
I am able to send youtube link from WLMessenger. Working fine here.
Zim
Security threat? Gosh. I’m not having that problem here yet.
Sawyer
no block here,beijing,CN
Douz
The theme of your blog is great , I like it very much ,But What is the name of this Theme ?can you mail me one ?or give me a address to download it BY EMAIL.. Thank you very much
wertigon
To all people saying that you can send Youtube links; Yes, it works now. Microsoft obviously fixed it.
However, it DIDN’T work yesterday. It wasn’t a regular expression fault either; Trying to send http://www.youfoobar.com or http://www.foobartube.com worked just fine. It was, quite specifically, http://www.youtube.com that was blocked.
Why? Ask MS, I have no idea myself.
link8583
There must be a server side security at microsoft that blocks URLs that are being sent too many times in a short timespan on wlm to avoid worms from spreading though messenger (like we’ve seen many times in the past, but not recently).
Maybe yesterday too many people sent exactly the same youtube URL by wlm and that triggered the blocking (since this is the exact behavior of an IM worm). And there is probably no whitelist telling that youtube is a trusted domain (no domain can really be trusted because of potential cross site scripting flaws).
Nish
Well… You could either change HTTP into HXXP or encrypt your IM Conversations…
http://www.nishv.com/2008/05/live-messenger-blocks-youtube-urls/
Fabeme
I was more thinking about a reverse DNS feature that turned bad. The fact that other domains were afected lead to that. Word filtering is useless on cross scripting attacks, IPs are the only valuable data you can treat with.
Manan
Liveside is reporting that some one from MS has said that this was due to the MS partner who takes care of filtering supposedly malicious links, MS had not asked for the filtering & from the posts it is quite clear that some were facing it and some weren’t so I doubt that this was an intentional doing but rather an accidental one.
Alex
http://www.googlepages.com is still blocked and http://www.ebuddy.com as well.
[03:15] Thunder: http://www.googlepages.com
[03:15] *** The following message could not be delivered to all recipients: http://www.googlepages.com
[03:58] Lexje (H): http://www.ebuddy.com
[03:58] *** The following message could not be delivered to all recipients: http://www.ebuddy.com
net neutrality
hooray for net neutrality!
vasudev
Here is the official explanation for it.
http://messengersays.spaces.live.com/blog/cns!5B410F7FD930829E!35340.e ntry
James
I must admit, I was quite surprised by the news of this - even from Microsoft. Quite why they think this is a smart business move is another issue entirely.
Xed
Accident my foot. This is why MS has/had blocked YouTube links:
http://www.reuters.com/article/technologyNews/idUSL1271038920080512
Andrew
They’re trying to block the spammers, which unless you’ve been under a rock, have been out in full force on messenger lately. Unfortunately, some sites will have their links sent thousands of times legitimately, like youtube, and they just need to exempt those sites and all will be well again.
redfish
Xed,
and how would intentionally blocking YouTube links for one or so days helped them with that?
Berno
Microsoft says YouTube blocking was a glitch
Users of Microsoft’s instant-messaging service found themselves unable to share links to YouTube videos on Friday evening and Saturday morning, sparking brief worries of a possible Microsoft-led effort to block access to the Google-owned video-sharing site. Microsoft said in a blog posting Sunday that the issue was a mistake made by the third party that handles blocking of potentially unsafe content for MSN Messenger and Windows Live Messenger. “As some of you noticed, we had a problem from Friday night to Saturday morning where our Messenger service was incorrectly blocking some legitimate IP addresses,” a Microsoft employee said on the company’s Messenger blog. “We sincerely apologize for any difficulties this caused our users.” The company thanked users to alerting it to the problem. “Because of your help, the incorrect block was only in place for a few hours.”
http://www.zdnetasia.com/news/software/0,39044164,62041269,00.htm
Calvin
Could this explain too?
http://news.softpedia.com/news/Australians-to-Say-Goodbye-to-Internet- Freedom-85549.shtml
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